鄂尔多斯盆地华庆油田长6储层水驱油特征及主控因素研究

Study on the characteristics of water displacing oil and main controlling factors in Chang 6 reservoir in Huaqing oilfield of Ordos basin

随着油田开发中对储层微观储层特征精细认识的需要,电子显微镜起着越来越重要的作用。本文以长63储层为例,应用X-衍射、扫描电镜、铸体薄片、恒速压汞和真实砂岩水驱油实验等实验手段,分析储层微观水驱油驱替类型和残余油特征,找出影响驱油效率的主控因素。研究表明:研究区主要有均匀驱替、指-网状驱替、指状驱替三种类型,驱替效率依次降低;残余油分布则以油膜状、角隅、卡断和绕流形式分布为主。储层物性、驱替倍数、微观孔隙结构、驱替压力和润湿性等因素都影响着驱替效率的高低,其中孔喉半径比是影响驱替效率的决定性因素。注水开发时,应注重将现场工艺与岩心水驱油实验相结合,合理设计开发工艺、分段开采高渗透带储层。

Electron microscopy plays an increasingly important role for the need of fine understanding of reservoir micro-reservoir characteristics in oilfield development. the Chang 63 reservoir is taken as an example in this paper,the authors quantitatively studied the flooding type,residual oil occurrence and main factor of controlling reservoir oil displacement efficiency by using X-ray diffraction,scanning electron microscopy,casting flakes,constant-speed mercury,water-flooding experiments with the real sandstone micro-model and so on. The results show that flooding types include homogeneous flooding,finger-reticular flooding and finger flooding in study area.Residual oil distribution are mainly residual oil film,residual oil flow around,pore edge and corner residual. petrophysical parameters,multiple of displacement microscopic pore structure,displacement pressure and wet ability are primary factors that affecting the effects of reservoir oil displacement. The pore throat radius ratio is the crucial factor that affecting the effects of reservoir oil displacement in pore characteristic parameters. This paper proposes that site technology and the core waterflooding seepage experiment should be emphasized in the process of waterflood development,and priority should be given to reservoir with high permeability in designing reasonable exploitation techniques and procedures.